import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

public class dgut implements Filter {
    public void destroy() {
    }

    public void doFilter(ServletRequest req, ServletResponse resp, FilterChain chain) throws ServletException, IOException {
        HttpServletRequest request = (HttpServletRequest) req;
        HttpServletResponse response = (HttpServletResponse) resp;
        String token = request.getParameter("token");
        if(token == null)
        {
            response.sendRedirect("https://cas.dgut.edu.cn?appid=javaee&state=STATE");
        }
        chain.doFilter(req, resp);
    }

    public void init(FilterConfig config) throws ServletException {

    }

}
